Major changes:
- Huge speed improvement for feature tracking by using https://github.com/chinue/Fast-SSIM
- Significantly reduced computational complexity for feature tracking step
- Removed option to choose subpixel estimator size, Gaussian 2x3 fit now default
Minor changes:
- Changes to console printing format, added progress bar
- Bugfixes in filter_frames.py
- Minor bugfixes in GUI
- Added docstrings and type hints in Python files